The present invention relates to a process for making an organosilicon compound containing an amino group, and more paticularly, to a process for making an organosilicon compound containing an amino group by reacting an allylamine with a silicon compound having hydrosilyl group, in the presence of a complex of platinum with an olefin or its derivative, and an amino compound within a defined scope, especially an aromatic amine compound. Also, the present invention provides a catalyst system which is high in reactivity for a wide variety of organosilicon compounds in the hydrosilylation reaction of allylamine.
For the preparation of an organosilicon compound containing an amino group, for example, an alkoxysilane containing a .gamma.-aminoalkyl group, there have been heretofore employed methods requiring a large number of reaction steps and also an expensive reducing agent. To use the example of .gamma.-aminopropyltriethoxysilane, acrylonitrile is allowed to react with trichlorosilane in the presence of an amine catalyst and a copper (I) chloride catalyst to obtain .gamma.-cyanoethyltrichlorosilane, which is then converted to an alkoxy derivative by reaction with ethanol, followed by reduction with an expensive reducing agent such as NaBH.sub.4 under high pressure to obtain .gamma.-aminopropyltriethoxysilane. When trialkoxysilane is used as the starting material, the yield of .gamma.-aminopropyltrialkoxysilane is markedly lowered.
As to the method in which allylamine is subjected to addition reaction with a silicon compound such as a silane or a siloxane having hydrosilyl group in the presence of a platinum catalyst, a large number of reports have been published. For example, N. S. Nametkin et al reported the reaction between triethoxysilane and allylamine in the presence of chloroplatinic acid, in which the yield of .gamma.-aminopropyltriethoxysilane after the reaction at 100.degree. C. for 6 hours was only 10% {Dokl. Akad. Nauk. SSSR. 140, 384 (1961)}, whereby allylaminotriethoxysilane is formed through side reactions to consume triethoxysilane. J. L. Speier reported the reaction with trialkoxysilane after protection of the amino group by trimethylsilylation, but such a method is not advantageous, because not only is the number of reaction steps increased, but also the yield of the silylation reaction is low to give a low total yield. West German Pat. No. 2,408,480 discloses a method in which an addition reaction is carried out to synthesize a cyclic silazane from a chlorosilane having hydrosilyl group and allylamine and the cyclilc silazane is cleaved with the use of an alcohol. However, this method is disadvantageous in that sufficient yield can only be obtained with difficulty, and cumbersome steps are required for removal of the salt.
Czechoslovakia Pat. Nos. 165,746, 193,448, 193,623, 194,149 and 200,379, U.K. Pat. No. 1,238,875 and East German Pat. No. 72,788 also disclose addition reactions between allylamine and alkoxysilane with platinum catalyst, but all of these methods employ chloroplatinic acid as the platinum catalyst and involve disadvantage such as requiring high temperature and long reaction time, for example, 125.degree. C. and 56 hours, and poor reproducibility.
Otherwise, as the method for preparation of .gamma.-aminopropyltrialkoxysilane, there is also the method in which .gamma.-chloropropyltrialkoxysilane is aminated with ammonia or an amino compound, as disclosed in U.S. Pat. No. 4,234,503, but this is a high pressure reaction and also includes disadvantageously a large number of reaction steps.